Whole-Genome Sequencing of Lysobacter capsici VKM B-2533T and Lysobacter gummosus 10.1.1, Promising Producers of Lytic Agents.

Lysobacter capsici VKM B-2533T and Lysobacter gummosus 10.1.1 are promising strains for use in biomedicine as sources of new antimicrobial agents. Here, we report the whole-genome sequences of both strains (total lengths, 6,239,188 bp and 6,056,609 bp, respectively), obtained using the Illumina and Nanopore platforms.

Deletion of alpB Gene Influences Outer Membrane Vesicles Biogenesis of Lysobacter sp. XL1.

Outer membrane vesicles (OMVs) produced by Gram-negative bacteria constitute important factors in defining interactions with the extracellular milieu. Lysobacter sp. XL1 produces OMVs capable of lysing microbial cells due to the presence in their cargo of bacteriolytic protease L5 (AlpB). Although protein L5 has been functionally and biochemically characterized (including aspects of its packing into OMVs), its role in vesicle biogenesis through genetic deletion of alpB had not been studied previously. Here, we have successfully deleted alpB by allelic replacement and show that the alpB deletion mutant produces a significantly lower amount of OMVs that lack bacteriolytic activity and display altered ultrastructural characteristics in relation to the OMVs produced by the wild-type strain. These results confirm that, as previously proposed, protein L5 participates in OMV production through a mechanism that is not yet fully understood.

Draft Genome Sequence of the Type Strain Lysobacter capsici VKM B-2533.

Lysobacter capsici VKM B-2533T is a promising strain for isolation of new lytic agents. Here, we report a draft genome sequence of this strain, consisting of 131 scaffolds with a total length of 6,196,943 bp. The results obtained will aid in the discovery and study of biologically active compounds important for biomedicine.

ß-Lytic Protease of Lysobacter capsici VKM B-2533T.

Bacteriolytic enzymes are promising antimicrobial agents for developing new-generation drugs. Recently, we have isolated a ß-lytic protease (BlpLc) from the culture liquid of Lysobacter capsici VKM B-2533T. This BlpLc possesses a valuable property, not described for ß-lytic proteases (Blps) earlier, of hydrolyzing living cells of Staphylococcus aureus 55 MRSA clinical isolate. This work phylogenetically characterized the BlpLc and investigated its properties. Analysis revealed a variability of pre-/pro-parts of Blp precursors. The mature BlpLc is the closest to the earlier annotated but not isolated Blp from Lysobacter sp. Root690. The biochemical characterization found conditions for the BlpLc general bacteriolytic activity relative to autoclaved S. aureus 209P cells to differ from that of earlier isolated Blp. Unexpected was the effect of serine (phenylmethylsulfonyl fluoride (PMSF)) and cysteine (p-chloromercuribenzoate (p-CMB)) protease inhibitors on BlpLc bacteriolytic and proteolytic activities. The specificity of BlpLc proteolytic action relative to hemoglobin, elastin, gelatin, collagen, azofibrin, myoglobin, ovalbumin, and ovamucoid was found. New types of peptide bonds-Gly-X, Ser-X, Lys-X, Ala-X, Val-X, Glu-X, and Phe-X-hydrolyzed by the enzyme in protein substrates were first revealed using MALDI-TOF. Turbidimetrically, the BlpLc was found to lyze living cells of S. aureus 209P, Micrococcus luteus B1819, and M. roseus B1236, which is important for expanding the enzyme's applied properties.